1. Field of the Invention
The present invention relates to an electromagnetic shielding layer and method for making the same and, particularly, to a carbon nanotube based electromagnetic shielding layer and method for making the same.
2. Discussion of Related Art
Carbon nanotubes (CNTs) are a novel carbonaceous material and received a great deal of interest since the early 1990s. CNTs are electrically conductive, chemically stable, and individually capable of having a very small diameter (much less than 100 nanometers) and a large aspect ratio (length/diameter). Due to these properties, along with others, it has been suggested that CNTs can play an important role in various fields, such as microscopic electronics, field emission devices, thermal interface materials, etc.
With recent developments in the electronics industry, various compact devices are increasingly prone to electromagnetic interference. To improve the security and performance of these devices, many electronic accessories in the compact device, along with its shell, should maintain a good connection with the ground. The shell of the device is usually made of plastic and contains a conductive coating, which is usually formed on the surface of the plastic material to shield the device from electromagnetic interference. The electromagnetic shielding layer is produced either by spraying or painting the conductive coating to the surface of the plastic material. The conductive material can be polymer, metal powder, graphite, and metal oxide, among others. However, the conductive coating is typically too thin to effectively shield the device from electromagnetic interference. The conductive coating must be thicker to properly shield the device from unwanted interference. One drawback, however, is that the cost of the conductive coating used to produce the electromagnetic shielding layer is high. Furthermore, if the conductive coating is too thick, the electrical conductivity thereof won't be as steady.
What is needed, therefore, is to provide an electromagnetic shielding layer with good electrical conductivity and a method for making the same.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate at least one embodiment of the electromagnetic shielding layer and method for making the same, in at least one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.